Data Sufficiency

BTGmoderatorDC wrote:Last week, Raina and Bob made a combined total of 190 sales at a computer store. Raina made how many more sales than Bob?

(1) The difference between the number of sales Raina made and the number of sales Bob made was ten percent of the number of sales Raina made.
(2) Bob made 9/19 of the total number of sales made by himself and Raina.

OA D

Source: Veritas Prep

Say Raina made R number of sales and Bob made B number of sales.

Thus, R + B = 190 ---(1)

We have to find out the value of R -B.

Let's take each statement one by one.

(1) The difference between the number of sales Raina made and the number of sales Bob made was ten percent of the number of sales Raina made.

=> R - B = 10% of R
R - B = R/10
B = 9R/10 ---(2)

From (1) and (2), we have can get the unique values of R and B, thus R - B. Sufficient.

(2) Bob made 9/19 of the total number of sales made by himself and Raina.

B = 9(B + R)/19

B = (9*190)/19 = 90

Thus, R = 190 - 90 = 100

Thus, R - B = 10. Sufficient.

The correct answer: D

Hope this helps!

-Jay
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